JPH02185588A - Additive for drilling mud - Google Patents

Abstract

PURPOSE:To obtain the title additive which can prevent adverse effects of various hardening components, sea water, etc., and can stabilize mud even which the addition in a small amount by copolymerizing a specified unsaturated monocarboxylic acid monomer with a specified unsaturated dicarboxylic acid monomer to form a water-soluble copolymer having a specified average molecular weight. CONSTITUTION:30-95mol% of at least one unsaturated monocarboxylic acid monomer (A) selected from (meth)acrylic acid and a monovalent metal salt, divalent metal salt, ammonium salt, and organic amine salt of said acids is copolymerized with 70-5mol% of at least one unsaturated dicarboxylic acid monomer (B) selected from maleic, fumaric and itaconic acids (anhydrides) and monovalent metal salts, divalent metal salts, ammonium salt, and organic amine salts of these acids (the sum of A and B is 100mol%) to give an additive for drilling mud, comprising a water-soluble copolymer having an average molecular weight of 1,000 to 5,000. Because of excellent salt resistance, this additive makes it possible to use sea water as well as water having a high hardening component content, such as groundwater, for soil conditioning; it hardly is affected adversely by groundwater, cement, and sea water when mixed therewith in drilling, so that mud can be stabilized by the addition thereof in a small amount.

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention is a method for stabilizing muddy water used in deep excavation of the ground, such as foundation work for civil engineering work and poling of oil wells and geothermal wells. Regarding additives.

(Conventional technology) Conventionally, when excavating the ground, it is necessary to absorb high frictional heat generated during excavation, carry excavated waste from the bottom of the pit to the ground, maintain the pit wall, or prevent the collapse of collapsible strata. The mud composition prepared in the above is continuously and cyclically injected into the excavation site.

Mud compositions typically include bentonite, attapulgite,
The mud is made using inorganic mud such as selinite and hydrated magnesium silicate, and additives for drilling mud to stabilize the water and mud.

Among the additives for drilling mud that have been conventionally used, sodium tripolyphosphate is an inorganic compound.

Condensed phosphates such as sodium hexametaphosphate; alkali metal carbonates such as sodium carbonate and potassium carbonate;
Examples include aluminates such as sodium aluminate and potassium aluminate. In addition, organic compounds include humate, lignin sulfonate, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HE
C), polyvinyl alcohol (PVA), and phosphonates, each of which has its own problems.

In other words, condensed phosphates have received relatively good reviews, but if they are used for a long period of time, they can diffuse underground and enter the ocean, lakes, etc., causing blue-green algae growth and red tide, so they have recently become less popular. Use is severely restricted. Although CMC also received relatively good reviews, it had a serious drawback in that the muddy water made using it was easily putrefied. alkali metal carbonate,
Aluminate, Amate, Lignosulfonate, H
EC, PVA, sulfonic acids, etc. had low effects.

In order to solve the above-mentioned problems that these conventional additives had,
No. 883, JP-A-58-208376, JP-A-58-
The use of polyacrylic acid (salt) has been proposed in JP-A No. 208377, JP-A-59-135280, JP-A-60-133085, JP-A-62-199682, and the like.

However, polyacrylic acid (salt) does not have sufficient salt resistance, so for example, when water with a high content of hardness components or seawater is used as water for mud production, or when muddy water in underground excavations is used, a large amount of groundwater or seawater is used. If the mud flows in, the viscosity of the mud will be significantly impaired, and in some cases it will turn into a gel, making it difficult to excavate.

A method for improving the above-mentioned drawbacks of such polyacrylic acid (salt) has also been proposed. For example, JP-A-58-
120683, JP 58-219289, JP 60-181187, JP 61-120881,
JP-A No. 62-267388 proposes additives for drilling mud made by combining polyacrylic acid (salt) with other ingredients, but although these additives have been improved somewhat, they are not sufficient. However, it is necessary to add a relatively large amount, and it cannot be said that the wood quality defects of polyacrylic acid (salt) are improved. Also, JP-A-58-104981, JP-A-61
The use of sulfonic acid group-containing copolymers has been proposed in No. 241382 and Japanese Patent Application Laid-open No. 215681/1983. The sulfonic acid group-containing copolymers disclosed in these documents have improved initial performance in terms of the wood quality defects of polyacrylic acid (salt), but are relatively susceptible to hydrolysis and therefore have high performance. There was a limit to its long-term use at high temperatures. Moreover, the sulfonic acid group-containing copolymers disclosed in these documents are generally expensive and require a relatively large amount of addition, which still leaves problems. (Problems to be solved by the invention) ) The present invention is an additive for conventional drilling mud that is added to stabilize mud used for deep excavation of the ground such as foundation work for civil engineering work and poling of oil wells and geothermal wells. This solves the above problems.

Therefore, the purpose of the present invention is to use a copolymer that can be industrially easily and inexpensively produced as an additive for drilling mud when drilling using inorganic mud such as bentonite and industrial water, thereby reducing the amount of additive added. In terms of quantity, groundwater
The purpose is to prevent the negative effects caused by various hardness components contained in cement, etc., and seawater.

(Means and Effects for Solving the Problems) The present invention is directed to the use of acrylic acid, methacrylic acid, monovalent metal salts, divalent metal salts, ammonium salts, and organic amine salts of monomers such as acrylic acid, methacrylic acid, and the like. , 30 to 95 mol% of one or more unsaturated monocarboxylic acid monomers (I) and (anhydride) maleic acid, fumaric acid, itaconic acid, and monovalent metal salts of these monomers. , 70 to 5 mol% of one or more unsaturated dicarboxylic acid monomers (■) selected from the group consisting of divalent metal salts, ammonium salts, and organic amine salts (However,
The total amount of the unsaturated monocarboxylic acid monomer (I) and the unsaturated dicarboxylic acid monomer (II) is 100 mol%. ) is the average molecular weight derived from the monomer component consisting of i,
The present invention relates to an additive for drilling mud comprising a water-soluble copolymer (A) of ooo to 5o and ooo.

Unsaturated monocarboxylic acid monomer (I
), for example, acrylic acid, methacrylic acid, or partially or completely neutralized products of these acids with monovalent metals, divalent metals, ammonia, or organic amines. Monovalent metals include sodium, potassium, etc., and divalent metals include calcium, magnesium, zinc, etc. Examples of organic amines include alkylamines such as monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, and triethylamine; alkanolamines such as monoethanolamine, jetanolamine, triethanolamine, monoisopropanolamine, and dimethylethanolamine. pyridine, etc.

In addition, as the unsaturated dicarboxylic acid monomer (II), maleic anhydride, maleic acid, fumaric acid, itaconic acid, or partially neutralized products of these acids with monovalent metals, divalent metals, ammonia, or organic amines can be used. Alternatively, a completely neutralized product can be given. Monovalent metals include sodium, potassium, etc., and divalent metals include calcium, magnesium, zinc, etc. In addition, organic amines include monomethylamine, dimethylamine, trimethylamine,
Monoethylamine-7 Alkylamines such as diethylamine and triethylamine; flukanolamines such as monoethanolamine, jetanolamine, triethanolamine, monoisopropanolamine, and dimethylethanolamine; and pyridine.

Among these, (anhydrous) maleic acid and partially or completely neutralized (anhydrous) maleic acid with a monovalent metal are particularly preferred.

The water-soluble copolymer (A) used in the present invention contains 30 to 95 mol% (preferably 40 to 90 mol%) of the unsaturated monocarboxylic acid monomer (I) and the unsaturated dicarboxylic acid monomer ( II) 70-5 mol% (preferably 60-10 mol%)
) with an average molecular weight of i,
It must be within the range ooo to 50,000.

If either the composition or average molecular weight of the monomer components is outside the above specified range, it will not be possible to obtain a water-soluble copolymer (A) that can exhibit high performance as an additive for drilling mud. For example, if the amount added is low, it will be difficult to prepare mud using groundwater, seawater, etc., and it will not be possible to prevent the adverse effects of groundwater, cement, and seawater inflow during excavation. Furthermore, problems arise in terms of heat resistance.

To obtain the water-soluble copolymer (A) used in the present invention,
These monomer components consisting of the unsaturated monocarboxylic acid monomer (I) and the unsaturated dicarboxylic acid monomer (II) may be polymerized using known techniques. For example, in the case of aqueous solution polymerization, sodium peroxide , persulfates such as potassium persulfate:
Hydrogen peroxide: Can be produced by a conventional method using a water-soluble azo compound such as 2.2°-azobis(2-amidinopropane) hydrochloride or 4.4°-azobis-4-cyanovaleric acid as a polymerization catalyst. In addition, alcohols such as methanol and isopropyl alcohol, tetrahydrofuran,
For polymerization in organic solvents such as ethers such as dioxane, aromatics such as benzene, xylene, toluene, or ketones such as methyl ethyl ketone and methyl isobutyl ketone, organic solvents such as benzoyl peroxide, lauroyl peroxide, peracetic acid, etc. Perliquated product; azobisisobutyronitrile, 2,
It can be produced by a conventional method using an oil-soluble azo compound such as 2°-azobis(4-methoxy-2,4-dimethylvaleronitrile) as a polymerization catalyst.

In addition, when obtaining the water-soluble copolymer (A), the unsaturated monocarboxylic acid monomer (I) and the unsaturated dicarboxylic acid monomer (II) may be used together within a range that does not impair the effects of the present invention. It is of course possible to copolymerize other polymerizable monomers. Other monomers that can be copolymerized include amide monomers such as (meth)acrylamide and t-butyl (meth)acrylamide; (meth)acrylic esters, styrene, 2-methylstyrene, vinyl acetate, etc. Hydrophobic monomers: vinylsulfonic acid, 3-allyloxy-2-hydroxypropanesulfonic acid, allylsulfonic acid, methallylsulfonic acid, styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, sulfoethyl (
meth)acrylate, sulfopropyl(meth)acrylate, 2-hydroxysulfopropyl(meth)acrylate, sulphoethylmaleimide, or partially or completely neutralized products thereof with monovalent metals, divalent metals, ammonia, or organic amines Unsaturated sulfonic acid monomers such as; 2
-Hydroxyethyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, allyl alcohol, polyethylene glycol monoallyl ether, polypropylene glycol monoallyl ether, α-hydroxyacrylic acid, N-methylol (meth)acrylate, ) acrylamide, glycerol mono(meth)acrylate, glycerol monoallyl ether, vinyl alcohol, 3-methyl-3-buten-1-ol (isoprenol), polyethylene glycol monoisoprenol ether, polypropylene glycol monoisoprenol ether,
3-methyl-2-buten-1-ol (prenol),
Polyethylene glycol monoprenol ether, polypropylene glycol monobrenol ether, 2-methyl-3-buten-2-ol (isoprene alcohol), polyethylene glycol monoisoprene alcohol ether, polypropylene glycol monoisoprene alcohol ether, etc. Hydroxyl group-containing unsaturated monomers Unsaturated dicarboxylic acid monomers such as ditraconic acid and aconitic acid Cationic monomers such as dimethylaminoethyl (meth)acrylate and dimethylaminopropyl (meth)acrylamide: (meth)acrylonitrile Nitrile monomers such as: (meth)acrylamide methanephosphonic acid, (meth)acrylamide methanephosphonic acid methyl ester, 2-(meth)acrylamide-2-
Phosphorus-containing monomers such as methylpropanephosphonic acid; ethylene, propylene, l-butene, imbutylene, α-amylene, 2-methyl-1-butene, 3-methyl-1-butene (α-inamylene), l- Examples include α-olefin monomers such as hexene and etheptene.

When these monomers are used, they are preferably used in an amount of O to 30% by mole based on the total monomers in order to fully exhibit the characteristics of the present invention. When using the water-soluble polymer (A) thus obtained as an additive for drilling mud, condensed phosphates, alkali metal carbonates, aluminates, humates, lignin sulfonates, CMC, HEC, PVA, It is free to use conventional drilling mud additives such as phosphonic acid.

(Effect of the invention) When the water-soluble copolymer (A) of the present invention is used as an additive for drilling mud, due to its excellent salt resistance, it can be used not only as fresh water but also as ground water and industrial water when preparing mud. Water with a relatively high hardness component content, such as commercial water, and seawater can also be used. In addition, during excavation, even if it comes into contact with or mixes with groundwater, cement, seawater, etc., the mud composition has no or little tendency to gel or thicken, and the amount of water removed does not increase significantly, resulting in an excellent mud wall. to form.

Furthermore, it exhibits excellent effects even when added in low amounts, and is inexpensive, making it possible to significantly reduce excavation costs, making it extremely valuable for industrial use.

The reason why the additive for drilling mud of the present invention exhibits excellent effects even in low addition amounts and is less susceptible to adverse effects from groundwater, cement, seawater, etc. is not clear, but it is speculated as follows. That is, the adjacent carboxyl groups in the unsaturated dicarboxylic acid monomer (II) exhibit a remarkable synergistic effect with the carboxyl group of the unsaturated monocarboxylic acid monomer CD, contributing to salt tolerance. It is considered. However, the present invention is not limited to this reason alone.

(Example) The present invention will be specifically described below with reference to Reference Examples and Examples, but the present invention is not limited to these Examples. In addition, in the examples, unless otherwise specified, all parts are parts by weight, and all percentages are percentages by weight.

Reference Example 1 453 parts of deionized water and 4 parts of sodium hydroxide were placed in a glass round bottom flask with a capacity of 1 fL equipped with a thermometer and a reflux condenser.
8 parts of maleic anhydride and 58.8 parts of maleic anhydride were added, and the temperature was raised to the boiling point of the system. 216 parts of 80% aqueous acrylic acid solution under stirring, 1
90 parts of a 0% ammonium persulfate aqueous solution and 30 parts of a 20% hydrogen peroxide solution were each dropped from separate dropping nozzles over a period of 4 hours. The temperature during the dropwise addition was controlled to be at the boiling point of the system throughout. After dropping, keep at the same temperature for 30 minutes.
The polymerization was completed by holding for a minute. After cooling, it was completely neutralized to P Hto using 48% sodium hydroxide.

The average molecular weight of the obtained water-soluble copolymer (A), the sodium salt of the acrylic acid/maleic acid = 80,720 (mole ratio) copolymer (water-soluble copolymer (1)), was 4,300. .

Reference Examples 2 to 18 and Comparative Reference Examples 1 to 14 Water-soluble copolymers (2) to (18) and comparative water-soluble (co)polymers (1) to (14) were obtained according to the method of Reference Example 1. Ta. The average molecular weights of these (co)polymers are shown in Tables 1 and 2.

Example 1 In a tank made of SUS304 with an inner diameter of 90 mmφ and a height of 160 mm, 100 parts of deionized water, 6 parts of bentonite, and a water-soluble copolymer (A) obtained in Reference Example 1 as an additive for drilling mud were prepared. Copolymer (1) is 0 in terms of solid content.
．． Take 2 parts and use a Daysilver stirring blade (blade diameter 40+am
φ) at 2000 rpm for 15 minutes to obtain a drilling mud composition (1).

*Note 1) Measured using a 500ml funnel viscometer.

Unit is seconds *Note 2) Measured with a fan VG meter. Unit is pascal *Note 3) 3 kg/a using a filter according to API standards
T? The amount of dehydration was measured after 30 minutes under this pressure.

The unit is m. 5 parts of cement is mixed with the above drilling mud composition (1), and after leaving it for one day, the funnel viscosity (FV), 10-minute gel strength (10Gel), and dewatering amount of the mud are measured. It is shown in Table 1.

Funnel viscosity (FV) of mud after mixing 4 parts of Aquamarine S (manufactured by Heshu Yakuhin, 25 times concentrated product of artificial seawater) with drilling mud composition (1) and leaving it for 1 day, 10 minutes Gel strength (10 Gel) and dehydration amount were measured and the results are shown in Table 1.

Examples 2 to 18 Drilling mud compositions ( 2) to (18) were obtained, and their physical properties, cement resistance and seawater resistance were evaluated, and the results are shown in Table 1.

Example 19 A drilling mud composition (18) was obtained in exactly the same manner as in Example 1, except that 0.1 part of carboxymethyl cellulose was used as a drilling mud additive, and its physical properties, cement resistance, and seawater resistance were evaluated. The results are shown in Table 1.

Comparative Examples 1 to 14 Comparative samples were prepared in the same manner as in Example 1, except that the comparative water-soluble (co)polymers (1) to (14) obtained in Comparative Reference Examples 1 to 14 were used as drilling mud additives. Compositions (1) to (14) were obtained and their physical properties, cement resistance and seawater resistance were evaluated, and the results are shown in Table 2.

Comparative Example 15 A comparative composition (
15) was obtained, and its physical properties, cement resistance and seawater resistance were evaluated and the results are shown in Table 2.

Comparative Example 16 A comparative composition (16) was obtained in exactly the same manner as in Example 1 except that only carboxymethyl cellulose was used as the additive for drilling mud, and its physical properties, cement resistance, and seawater resistance were evaluated. The results are shown in Table 2.

Comparative Example 17 A comparative composition (17) was obtained in exactly the same manner as in Example 1 except that no additive for drilling mud was used, and the physical properties of this composition were
The cement resistance and seawater resistance were evaluated and the results are shown in Table 2.

Claims (1)

[Claims] 1. Acrylic acid, methacrylic acid and monomers thereof
30 to 95 mol% of one or more unsaturated monocarboxylic acid monomers (I) selected from the group consisting of valent metal salts, divalent metal salts, ammonium salts and organic amine salts and (
anhydride) one or more unsaturated dicarbons selected from the group consisting of maleic acid, fumaric acid, itaconic acid, and monovalent metal salts, divalent metal salts, ammonium salts, and organic amine salts of these monomers. Acid monomer (II) 70-5 mol%
(However, the total amount of unsaturated monocarboxylic acid monomer (I) and unsaturated dicarboxylic acid monomer (II) is 100 mol%
It is. ) A water-soluble copolymer (A) having an average molecular weight of 1,000 to 50,000 derived from a monomer component consisting of (A). 2. Unsaturated monocarboxylic acid monomer (I) 40-90
Mol% and unsaturated dicarboxylic acid monomer (II) 60-1
The additive for drilling mud according to claim 1, which is derived from a monomer component consisting of 0 mol%. 3. The additive for drilling mud according to any one of claims 1 to 2, wherein the unsaturated monocarboxylic acid monomer (I) is acrylic acid (salt). 4. Unsaturated dicarboxylic acid monomer (II) is maleic acid (
The additive for drilling mud according to any one of claims 1 to 3, which is a salt). 5. The additive for drilling mud according to any one of claims 1 to 4, wherein the drilling mud is bentonite mud.